AskSia

Plus

有一铁的氧化物样品，用

80 \mathrm{~mL} 5 \mathrm{~mol} \cdot \mathrm{L}^{-1}

的盐酸恰好完全溶解，所得...

Mar 19, 2024

有一铁的氧化物样品，用

80 \mathrm{~mL} 5 \mathrm{~mol} \cdot \mathrm{L}^{-1}

的盐酸恰好完全溶解，所得溶液还能与通入的

0.56 \mathrm{~L}

氯气 (标准状况) 反应，使

\mathrm{Fe}^{2+}

全部转化为

\mathrm{Fe}^{3+}

，则此氧化物为 A.

\mathrm{Fe}_{2} \mathrm{O}_{3}

\mathrm{Fe}_{3} \mathrm{O}_{4}

\mathrm{Fe}_{4} \mathrm{O}_{5}

\mathrm{Fe}_{5} \mathrm{O}_{7}

Key Concept

Stoichiometry and gas laws

Explanation

The amount of HCl used and the volume of Cl₂ gas reacted with the solution indicate the stoichiometry of the iron oxide. The reaction of HCl with iron oxide produces Fe²⁺, which then reacts with Cl₂ to form Fe³⁺. Using the molarity and volume of HCl, we can calculate the moles of HCl and then use the stoichiometry of the reaction to find the moles of Fe in the oxide. The volume of Cl₂ gas at standard conditions (0°C, 1 atm) can be converted to moles using the ideal gas law. The ratio of moles of Cl₂ to Fe²⁺ gives the stoichiometry of the iron oxide, which corresponds to Fe₃O₄.